Nine estimates of US coal resources have been published in the past 71yr. Although many details of these estimates differ markedly, those for 1913, 1922, and 1974 are surprisingly similar. Some differences are due to increased data, others reflect changes in terminology, definitions, criteria, guidelines, and methodologies. Thus many early estimates are not particularly useful in modern resource assessments. Preliminary definitions that are being prepared in 1980 by the US Geological Survey are compared with those published in 1976 and currently in use. Anticipated results of the new definitions are: 1) to lessen existing confusion about estimation procedures; 2) to make such procedures easier and more precise; 3) to promote use of a commonly accepted terminology accompanied by standardized definitions, criteria, guidelines, and methodologies for estimating resources. -Author
Additional publication details
Historical review of and current progress in coal-resource estimation in the United States.